Turkey wants to establish a safe zone in the 91km area stretching from Jarablus to Azaz to the west and says it will continue with the cross-border operation until "all terrorist elements are eliminated" from the region.

Turkey's operation, which involves tanks, fighter jets and special forces, is targeting both ISIL but also Syrian Kurdish forces that have been key to driving ISIL fighters out of other parts of the Syrian-Turkish border.

The Kurdish YPG militia is a key partner of the US-led coalition against ISIL, and has recaptured large swaths of territory in Syria from the group.

Yet, Ankara considers the YPG a "terrorist" group and has been alarmed by its expansion along the border, fearing the creation of a contiguous, semi-autonomous Kurdish region in northern Syria.

Last month, The US defence secretary has called on Turkey and Kurdish forces in northern Syria to stay focused on fighting ISIL and not to target each other.

Turkey in ‘largest-ever offensive’ against Kurdish fighters

Turkey, in response, said it would continue to target the Kurdish militia if it failed to retreat east of the Euphrates River.

Meanwhile, NATO Secretary General Jens Stoltenberg said on Friday that he welcomed Turkey's efforts against ISIL in northern Syria without mentioning its clashes with Kurdish fighters in the same region.

"We welcome Turkey's increasing efforts to fight against Daesh," Stoltenberg told Turkish broadcaster NTV, using an Arabic acronym for ISIL, also known as ISIS.

"Turkey has a right to defend itself," he said. "There have been many terrorist attacks coming from the Syrian side."